Answer:

Step-by-step explanation:
First determine whether it is a sine function or a cosine function. Since
sin(x) = 0 at x = 0 and we see indeed that the value of the function is 0 at x = 0 it must be a sine function
The general equation of a sine function is 
where a is the amplitude. The amplitude is one-half the difference between the lowest and highest values in the graph.From the graph we can see that the highest value is 3/4 and lowest is -3/4 so the amplitude = 1/2 (3/4 + 3/4) = 3/4
If the amplitude were positive, the function would be increasing at (0,0) and going up to its amplitude value. However we can see that the function is decreasing at (0,0 ) and goes down to -3/4. Therefore the amplitude a has a negative sign so a = -3/4
To compute b, note that the period of the function ie where it finishes a full cycle is 3π since the function at that x value repeats itself. The relationship between b and the period is 2π/b = 3π in this particular case
This gives b = 2/3
So a = -3/4, b = 2/3 and the equation is 
Answer:
I don't really get your question. But if you save the same amount each week. The amount of money will be the amount you save each week multiplied by the number of weeks
Let's break this down:
Total Pictures = 77
Drew's Pictures = X (An unknown amount)
Danielle's Pictures = 17 + 2X (2 times the amount of Drew plus 17)
So, let's put the pieces together, the problem should look like this:
Total Pictures = Drew's Pictures + Danielle's Pictures
So let's put in what we know:
77 = X + (17 + 2X)
1st step is to get X to one side:
77 = X + 17 + 2X
-17 - 17
=> 60 = X + 2X
=> 60 = 3X
Now that X is on one side, the 2nd step is to get X to be alone:
60/3 = 3X/3 (We have to divide to each side because the answer is equal)
20 = X
So, now that we know what X equals, let's go back to what we broke down:
Drew's Pictures = X (An unknown amount)
Danielle's Pictures = 17 + 2X (2 times the amount of Drew plus 17)
*Remember that X = 20*
So the amount of Drew's Pictures (since the amount is equal to X) is 20.
Danielle had 17 + 2X pictures which means:
17 + 2(20)
17 + 40
57
So Danielle took 57 pictures
Answer:
4
Step-by-step explanation:
2+2 is 4
Distribute: - (-3y)
You’ll now get y + 3y
Combine like terms and you’ll get 4y
(I maybe wrong but I think this is probably the answer)